Duplicator



Patented Oct. 17, 1939 PATENT y OFFIQE DUPLICATOR Albin B. Wahlquist,and Otto De Cardy, Chicago, Ill., assignors to The Heyer Corporation, acorporation of Illinois Application October 21, 1936, Serial No. 106,722

6 Claims.

This invention relates to duplicators and more particularly to that partthereof relating to the means of holding and locking the gelatin sheettaut and the combination of securely attaching the duplicator to any.convenient flat surface.

Duplicating machines are composed of an oblong base, usually with a feltcovering thereon, a gelatin sheet to which ink is applied, and means forstretching and holding the gelatin sheet taut. VThe master sheet, ofwhich copies are to be made, is placed upon the gelatin sheet in orderto impart to the sheet the printed matter appearing on the master sheet.Thereupon plain sheetsgare successively pressed against the gelatinsheet to receive an imprint and thereafter are removed. The gelatinsheet, being markedly adhesive, tends to be drawn away from the board towhich it is attached unless it is securely aflixed or locked in somesuitable manner.

Various devices have heretofore been used for holding the gelatin sheettaut and for locking the same, but as to the latter all the methodsemployed have been unsatisfactory either in that the adhesiveness wastoo great so as to pull the gelatin sheet away from the duplicatorboard, or it was necessary to have a locking device which was cumbersomeand expensive.

It is therefore an object of our invention to produce a duplicator whichwill hold the gelatin sheet and the like taut, and which will securelyand unquestionably lock the same and prevent the gelatin sheet becomingremoved from the duplicator board,

A further object is to provide the aforesaid locking means in a simplemanner which does not even require any screw or frictional contact andwhich will not be cumbersome to operate and which will be veryinexpensive to manufacture.

A further object is to provide means for quickly and readily securingsaid duplicator to any at surface, horizontal or vertical, which willhave sufficient strength to overcome the pronounced adhesive tendency ofthe sheets as they receive the imprint from severing the Contact betweenthe duplicator board and the surface to which it is applied.

'I'hese and other objects will more readily appear from the drawing inthe light of the following specification, in which drawing:

Fig. l is a plan view of our improved duplicator.

Fig. 2 is a side elevation of the same showing in full lines the lockingdevice in fixed or operative position, and in dotted lines in a raisedposition.

Fig. 3 is a perspective View of the gelatin sheet.

Fig Llis an enlarged elevational view of the tensioning and lockingmechanism.

Fig. 5 is an elevational view taken on the corner edge of the duplicatorwith the rtensioning 5 and locking device in raised position.

Fig. 6 is a corner and elevational view of the duplicator with thegelatin sheet in position.

Like characters are applied to similar parts in each of the respectivedrawings, in which I is the 10 base or board of the duplicator, made ofwood or metal, said base normally having a covering of felt or similarmaterial not shown on the drawing; 2 is the gelatin sheet; 3 is thesubstantially U-shaped metal edge to'which the gelatin sheet 15 isattached for cooperative contact with the lateral flange 4 on the end ofthe duplicator board;

5 is a bar for cooperative contact with the U- shaped metal edge 6 ofthe gelatin sheet; 'I is the side-piece of the tensioning and lockingdeo vice secured to the duplicator board by the screw 8; 9 is a pinserving to limit the downward direction of the toggle arms; I0 is a slotin the side-piece 'I; II is an aperture in one arm of the toggle; I2 isthe end of the bar 5 journaled in ,25 the aperture I I; I3 is one arm ofthe toggle arm journaled at I4 to the other arm I5, which arm is in turnjournaled to the side piece 1 and the duplicator board I at I6 by meansof the screw I 'I I8 is a knob attached to the journal I Il; I9 30 isthe channel formed by the U-shaped member 6; 2i] is the similar channelformed by the edge 3; 2| is the metal plate lremote from the tensioningand locking mechanism secured to the end of the board I by means of thescrew 22;V 23 .35 are rubber suction cups attached to the duplicatorboardvby means of the screws 2li; 25 are the concave ears of said cup;and 26 is a recess in the interior of said cups.

The device functions in the following manner: The gelatin sheet (Fig. 3)is first hooked over the edge remote from the tensioning and lockingmechanism, as shown in Fig. 6,'by having the lateral ange 4 engage thechannel member 20 of the metal edge 3. Thereupon the channel 45 memberVI!! of themetal edge 5 is engaged by the bar 5 within said channelmember, the tensioning and locking mechanism being in raised orinoperative position as shown in Fig. 4. Thereupon the tensioning andlocking mechanism is 50 pressed downward by means of the knob I8. Sincethe toggle arm I5 is fixed stationary by means of being journaled at I6to the side of the duplicator base, the toggle arm I3 when the knob I8is pressed downward tends to move outwardly 55 on the base I.

in the slot l of the sidepiece 1. This action tends to tension thegelatin sheet 2 and holds it taut The downward direction as pressure isapplied to the knob I8 is arrested by the pin 9, which is carefullylocated at the point so that when the toggle arms come in contact there-With, the alignmentof said arms causes an angle slightly less than 180degrees. This produces a bracing or counteracting effect when theadhesive tendency of the gelatin sheet tends to exert a pull tending toloosen the gelatin sheet. In practice it has been found that thislocking mechanism is very effective and will hold the gelatin sheet tautin locked position until pressure is applied by hand'on the knob I8 forthe purpose of disengaging the locking effect. If the pin 9 werepositioned in such manner that the angle of the toggle arms was 180degrees rather than somewhat less, the tension of the gelatin sheet 2would be relaxed to such an extent as to make the locking deviceinoperative. A

The adhesive tendency ofthe gelatin sheet to stick to the sheets beingapplied thereto is quite pronounced so that lof necessity the duplicatorbase must be securely affixed to some horizontal or vertical surface.While this could be done permanently by means of screws ornails, yetthese duplicator bases are Very commonly used on desks and in the schoolroom; consequently fastening the same by means of screws or nails is outof the question. We have therefore utilized a compound rubber suctioncup of concave shape as shown in Fig. 2, having a further recess 26which when the board is iirmly pressed or thrown forcibly against a flatsurface tends to eliminate any air between the inside of the cup and theflat surface. Then when the tension or force is removed, the cup beingmade of rubber having a comparatively strong tension, a tendency towardsa vacuum is created which will securely aflix the duplicator board tothe iiat surface. This suction adhesion is tremendously intensified bymeans of the recess 2'6 which tends to form a vacuum within a lvacuumwith the result that the adhesive connection between` the duplicato-rboard and the at surface to which it is attached is very pronounced.Obviously this strong adhesive tendency is very useful and necessarywhen used in combination for printing duplicate sheets. Furthermore,these suction cups also serve the further purpose of serving as acushion whereby the imprint is decidedly enhanced.

Having thus described our invention, what we claim is new and desire tosecure by Letters Patent is: Y

l. A portable duplicator comprising a base, means for connecting theretoa gelatin sheet and the like, and a toggle mechanism for stretching saidsheet situated intermediate the ends of said base, said toggle mechanismbeing capable of extending its opposing arms beyond a straight linewhereby a locking action is obtained.

2. In a device of the class described, a board having an edge at one endthereof for cooperative engagement with a U-shaped trough or channelattached to a gelatin sheet, an edge at the other end of said board forsimilar engagement with a similar U-shaped trough at the other end ofsaid gelatin sheet, said last named edge or bar having cooperativeconnection with one arm of v a toggle mechanism, said mechanism adaptedto press said gelatin sheet exteriorly when force or pressure is exertedagainst said toggle mechanism.

3. In a device of the class described, a board having an edge at one endthereof for cooperative engagement with a U-shaped trough or channelattached to a gelatin sheet, an edge at the other end of said board forsimilar engagement with a similar U-shaped trough at the other end ofsaid gelatin sheet, said last named edge or bar having cooperativeconnection with one arm of a toggle mechanism, said mechanism adapted topress said gelatin sheet exteriorly when force or pressure is exertedagainst said toggle mechanism, and a pin located on the side of saidboard directly in the path of the arms of said toggle mechanism, thesaid pin being positioned below a horizontal line drawn between theextremities of the two arms of said toggle mechanism in extendedposition. y

4. In a device of the class described requiring no separate table orbase or separate attaching means, means for connecting thereto a gelatinsheet, and a toggle mechanism consisting of two arms pivoted together atone end of said arms, the second end of one arm pivotally connected tothel side of said base and the other end of the second arm movablymounted in a slot at the side of said base for the purpose of stretchingsaid sheet, said toggle mechanism situated intermediate the ends of saidbase.

5. In a duplicator the combination of a base made integral with saidduplicator and requiring no supporting table or attaching means, agelatin sheet and a toggle mechanism for stretching said sheet, saidtoggle means supported by andattached to said base and situatedintermediate the ends thereof and comprising two arms pivoted togetherat one end of each of said arms, the other end of Yone of said armsbeing pivoted at a xed place in the side of said base and the other endof the second arm adapted for sliding action in a slot in the side ofsaid base.

6. In combination a duplicator consisting of a base made integraltherewith, a gelatin sheet, means for removably attaching one end ofsaid gelatin sheet to one end of said base, a pair of togglemechanismssituated on the side of said base intermediateV the ends thereofcomprising two arms pivotally connected, the other end of one armpivotally journalled to one side of said base, the other end of saidsecond arm pivotally connected to a bar extending transversely of'saidbase, said bar adapted to receive the other end of said gelatin sheetand adapted for longitudinal movement in a slot at each side of saidbase.

ALBIN B. WAHLQUIST. OTTO DE CARDY.

